Gold Nanoparticle-Quantum Dot Fluorescent Nanohybrid: Application for Localized Surface Plasmon Resonance-induced Molecular Beacon Ultrasensitive DNA Detection

Abstract

In biosensor design, localized surface plasmon resonance (LSPR)-induced signal from gold nanoparticle (AuNP)-conjugated reporter can produce highly sensitive nanohybrid systems. In order to retain the physicochemical properties of AuNPs upon conjugation, high colloidal stability in aqueous solution is needed. In this work, the colloidal stability with respect to the zeta potential (ZP) of four negatively charged thiol-functionalized AuNPs, thioglycolic (TGA)-AuNPs, 3-mercaptopropionic acid (MPA)-AuNPs, l-cysteine-AuNPs and l-glutathione (GSH)-AuNPs, and a cationic cyteamine-capped AuNPs was studied at various pHs, ionic strength, and NP concentration. A strong dependence of the ZP charge on the nanoparticle (NP) concentration was observed. High colloidal stability was exhibited between pH 3 and 9 for the negatively charged AuNPs and between pH 3 and 7 for the cationic AuNPs. With respect to the ionic strength, high colloidal stability was exhibited at ≤104 μM for TGA-AuNPs, l-cysteine-AuNPs, and GSH-AuNPs, whereas ≤103 μM is recommended for MPA-AuNPs. For the cationic AuNPs, very low ionic strength of ≤10 μM is recommended due to deprotonation at higher concentration. GSH-AuNPs were thereafter bonded to SiO2-functionalized alloyed CdZnSeS/ZnSe1.0S1.3 quantum dots (SiO2-Qdots) to form a plasmon-enhanced AuNP-SiO2-Qdots fluorescent nanohybrid. The AuNP-SiO2-Qdots conjugate was afterward conjugated to a molecular beacon (MB), thus forming an ultrasensitive LSPR-induced SiO2-Qdots-MB biosensor probe that detected a perfect nucleotide DNA sequence at a concentration as low as 10 fg/mL. The limit of detection was ~11 fg/mL (1.4 fM) while the biosensor probe efficiently distinguished between single-base mismatch and noncomplementary sequence target.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-016-1748-3) contains supplementary material, which is available to authorized users.

In vitro investigation of the effects of boron nitride nanotubes and curcumin on DNA damage

“…Zeta potential analysis is important to determine the surface charge of nanoparticles and to predict in vivo fate of nanoparticles because of their cellular interaction related to activation, agglutination, adhesion and for colloidal nanoparticle stability which is described as highly unstable (±0-10 mV), relatively stable (±10-20 mV), moderately stable (±20-30 mV) and highly stable (±30 mV), respectively [19][20][21]. The zeta potential of BNNTs dispersion was detected as −50,9 mV ( Fig.…”

Affinity Sensors for the Diagnosis of COVID-19

“…Moreover, some nanomaterials were applied to establish the optical aperture and reach very sensitive virus identification by SPR method combined with colorimetric and fluorescence determination based approaches [ 86 ]. Kinds of plasmonic nanomaterials can alter from metallic nanoparticles and quantum dots to graphene nanostructures [ 95 , 96 , 97 , 98 ].…”

Recent Progress in Plasmonic Biosensing Schemes for Virus Detection

“…Likewise, the large surface area-to-volume ratio provides a higher loading of biological receptors [ 14 , 34 , 35 , 36 ]. Depending on their chemical composition, dimension, and physical properties, common types of plasmonic nanomaterials can vary from metallic nanoparticles and quantum dots to graphene nanostructures (i.e., carbon nanocomposites: Nanotubes, nanosheets, nanoflowers) [ 14 , 37 , 38 , 39 ]. Since the number of nanomaterial-based applications for viral sensing has increased significantly in the last decade, a comprehensive review of recent developments on plasmonic platforms is presented below and summarized in Table 1 .…”